My '05 convertible has 52k miles, and the hydraulic timing chain (not belt) tensioner has failed for the third time in the last 5000 miles or so. The first was under warranty. The second time I called the dealership before the mileage hit 50k, but by the time of the appointment it was over 50k. They replaced it under warranty as a courtesy. Now, 3 weeks later, it's failed again. I have an appointment with the dealership next week. My concerns are:

1) Can I safely drive the car in the interim? (It is loud, but seems to drive normally.) I drive a fairly high number of miles. Right of the bat the drive to the dealership is 2 hours., so that's a given unless I have the car towed there. If I drive the car regularly besides that I will be putting an additional 600 miles or so on it before the appointment. I do not want to risk either engine damage, or being stranded if the tensioner fails completely. Is either scenario likely?

2) What might cause repeated failures of the timing chain tensioner? I assume at this point that the failure of this tensioner is actually a symptom of an underlying issue that is causing multiple failures.

3) Is there any scenario where the dealer can blame my MiniMania pulley or K&N air cleaner (HAI) for this? They are the only 2 non-stock parts, and have been on the car since it was only a couple of months old.

4) Since the car has now gone over 50k (but the issue began under 50k), can I expect Mini to hassle me over replacing whatever may have been the underlying cause all along under warranty?

Your input is greatly appreciated.

 

funny, this was an issue for me when i had my rmw cam put in. i'd call eric at helix and ask him. he told me these things are notorious for failing. fortunately it's not a pricey part.....but why yours is failing repeatedly is concerning. please let us know what the outcome is/was.

 

The dealer should replace it under warranty, if they replace a part, and claim it is fixed only to have it break again, they still have to fix it. That is the general rule at least.

 

I think that any parts that are put in by the dealer come with a 15,000 mile warranty regardless of mileage on the car. Think of it like this. If you paid to have it replaced and it immediately failed, wouldn't you expect that they make it right?

In your case it seems there is something causing this that they have not addressed yet and should have when you were under the 50K mark.

Rich

 

it just came back to me.....my problem was the "tensioner plunger" these things appear to be quite prone to failing.

 

Not really, maybe you have something else wrong. Maybe an oiling problem to the tensioner piston or just low oil pressure in general???

 

Bringing this one back from the dead.

I too may have to replace this. Can someone confirm that this noise sounds like the old 22R Toyota motors that needed chains/guides/tensioners?
Kinda like a "slapping" of the chain around. I've even had a fellow MINI driver ask if I had a diesel.
It goes away as you approach higher RPMs?

Chad, or any others, is this ( the plunger/piston ) a hard thing to change?
I think when I do my clutch in a couple weeks that this will need to be done too.

PS I have good oil pressure. Same as it always has been. And I have changed my oil no later than 7k mi. Always. Even under service period.

 

It takes a shallow 19mm socket; factory torque is always over the top so it does require leverage to remove and will take skin off for sure when it breaks free. The oil/coolant exchanger is in the way making it difficult to get the socket on good enough not to bugger the bolt head. For this reason I also remove the right front wheel to see if the socket is in place. I seems like each MCS is different as to what’s in the way of the bolt so have a variety of extensions on hand. For my car I use a shallow 3/8ths drive socket, universal, short extension, ½ in to 3/8ths adaptor, and long handled flex head ½ in drive ratchet to break free, and then the socket and extension to tighten with torque wrench. I would love to hear of a better way

I’ve read about failures on the track in Europe when plungers have been re-used, I now put a new one in after camshaft or head replacement.

 

Thanks for the quick reply.

I probably will have the motor out of the car as it will be lots easier to do all of this.

Now, I know that the guides will require the front cover of the motor to be removed. Has there been any reports of grooves worn in these? I would think with strict synthetic oil use, this would be very slim to none. Of course, with my luck, i've got ones with some weak material.

Once I passed the 50k mi mark, it seems everything is failing.

 

Also, what else on that side of the motor could be rattling? Oil pump?

The SC was taken off about 3k mi ago and oil levels were checked and topped. Front and rear. This was after finding the front of the oil pan wet with SC oil - water pump side.

 

To remove the guides, the camshaft sprocket comes off, the plugs on the side of the head unscrew, and the bolts are behind them, guides come up through the top.

 

Holy cow... don't think I will be doing all that- this time. Although, that would the perfect time to replace the cam. Hey, it's only money right?

I'm guessing it's just the tensioner plunger assembly as there have been no reports of the guides wearing through.
Thanks very much for the insight/help, Keith.

 

If anyone has replaced this can you tell me if the black plastic piece comes off before you put it in. when I pulled the old one out it had it on there so i left it on the new one but the noise didn't go away so i'm thinking it was installed wrong to begin with.

 

The new replacements are compressed and oil pressure has to open them. My mini tech buddy told me that if you take something and lever the chain guide (this was while replacing the cam so the valve cover was off) a tiny bit towards the new compressor, it unlocks it so you don't have the clacking before the oil pressure comes up. After a min or so, either way it should be quite, but until it opens, there is no tension and lots of chain slop.
For me my attempt to open it seemed to work as the car sounded normal with the cold start.
I also remember somewhere you can order different sizes. I think that was for the R56 engines, but maybe there are different sizes to be used as the chain ages and stretches.

 

I have read about decompressing it before but my question is do i need to remove the black plastic piece before i put it in.
The old one i pulled out had it on there but someone else could have installed one wrong.
It seems weird that a small plastic piece would be supporting the tensioner plunger.

here is a pic of a new one w/ the black plastic piece....

 

That piece goes on.

 

alrighty then I guess I will pull it out tomorrow and see if it ever decompressed. If it has then maybe the tensioner wasn't my problem to begin with.

 

may i ask what kind of noise it makes when the tensioner is failing?